NZ260826A

NZ260826A - Use of phosphorous acid or a salt thereof as a fungicide for plant propagation material and seeds

Info

Publication number: NZ260826A
Application number: NZ260826A
Authority: NZ
Inventors: Maurice Chazalet; Jacques Mugnier
Original assignee: Rhone Poulenc Agrochimie
Priority date: 1993-06-23
Filing date: 1994-06-23
Publication date: 1996-02-27
Also published as: ES2070792B1; HUT67998A; GB2279252B; AU6484994A; DK74494A; IT1269941B; DE4422025B4; ITMI941312A1; SI9400260B; IE80905B1; GR940100307A; PT101533B; BE1008436A5; FR2706736A1; HRP940363B1; JPH0759411A; RU2140728C1; FR2706736B1; IL110068A0; LU88502A1

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number £60826 260826 Priority Date(s): Complete Specification Rled: Class: 2 7 FEB 1996 Publication Date:. P.O. Journal No; il±Q.) NO DRAWING No.: Date: NEW ZEALAND PATENTS ACT, 1953 COMPLETE SPECIFICATION FUNGICIDAL SEED TREATMENT USING PHOSPHOROUS ACID OR ITS SAUK* • We, RHONE-POULENC AGROCHIMIE, a French body corporate of 14-20 Rue Pierre Baizet, BP 9163 Lyon 09, 69263 Lyon Cedex 09, FRANCE hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the statement:- - 1 - (followed by page -la-) 260 1Q Fungicidal seed treatment using phosphorous acid or its salts. The present invention relates to the protection of plant seeds and propagation material, including more especially monocotyledon plant seeds, against attacks from fungal diseases, and to compositions useful for this purpose. It is Xnown that it is possible to control fungal diseases of plants by foliar application of phosphorous acid and its derivatives (Patent GB 1,459,539) but this application has not been used in practice because of the phytotoxicity of compositions containing these ingredients (European Patent Application 230,209). It has now surprisingly been found that it is possible to obtain compositions having a good protective effect on seeds, and plants resulting from the germination of these seeds, by protecting the seeds vith phosphorous acid or a derivative thereof, without this protection being disturbed by excessive * phytotoxicity. 260826 1 As used herein, the term "seeds" includes any generative part (propagation material) of the plant which can be used for the reproduction of the latter. This includes not only seed grains (seeds within the narrow meaning), but also rhizomes, fruits, tubers, bulbs, plant parts, germinated plants, cuttings, cell cultures and artificial seeds such as, for example, those described in Patent Application WO 94/24847 or PCT/FR 91/00984 (published under the number WO 92/10087). The invention provides plant seeds or other propagation material, excluding seedlings or roots, comprising, as a fungicide, phosphorous acid or a salt thereof. The present invention more specifically provides natural or artificial seeds, preferably of monocotyledon plants, and other propagation material, excluding seedlings or roots, comprising, on or inside, as fungicide phosphorous acid or a salt thereof. The presence of another fungicide is not necessary, and in particular the triazole 2- (4- chlorobenzylidene) -5,5-dimethyl-l- (1H-1,2 ,4-triazol-l- ylmathyl)-l-cyclopentanol (the use of which with a second fungicide which may be inter alia phosphorous acid or a phosphite salt is described in European Specification No. 467792) is not used, but the presence of other fungicides is optional as described below. Phosphorous acid, also known as phosphonic acid, has the formula H-P(O) (OH)2 (abbreviated as EjPO«) • Its salts are known as phosphites, and can be/f^1 ° ^ r v c'\ mono- or disalts, preferably alkali metal or ammonium ^ \ | N -r\ )/ salts, in particular Na^POj, FyHPOj or NH,H2P03. v .. \Y,0!■ 26 0 8 28 3 On a practical level, the effective amount of phosphorous acid or salt thereof is generally between 1 g/q and lkg/q (q is the abbreviation of quintal = 100kg), preferably between 5 and 500 g/q. 1 to 500 g of active material per quintal of seed grain and preferably 5 to 300 g/quintal. The active material of phosphorous type is preferably chosen such that"its solubility in water at 20°C is greater 10 than 0.1g/l, more preferentially still greater than 0.5 g/1 and more preferentially still greater than 50 g/1. Active materials of lower solubility can also be used but it is then necessary to use fairly complicated formulations, for example wettable powders or aqueous suspensions. The use of active 15 materials of sufficiently high solubility as it has just been defined is advantageous in that it makes it possible to treat seeds using simple solutions, which is extremely economic. According to a first variant, the invention further relates to young plants resulting from the germination of the 20 seeds which i?.ave just been defined, these young plants being at the one- or two-leaf stage. That such young plants are obtained is all the more remarkable since it could be expected that the 5 The seed grains are preferably coated in a proportion of 2608 3a residual phosphorous acid has a phytotoxic effect with respect to plants resulting from the germination, in the same way that it had a phytotoxic effect in foliar treatment. The invention is particularly advantageous in protecting, against fungal diseases, seeds corresponding to crops included in the group comprising cereals, in particular wheat, barley, rye, winter barley, oats, triticale, maize or rice. The invention is particularly advantageous in protecting seeds against * diseases belonging to the group comprising Pvthiua arrherr>mar>*a. Pyt-.h-inm tj-rftm-iniccla. rtyt-hiiim f-nrii 7 nanm r Vyi-h-fnm van1-t»rVOOlli , Pyt-h-inm my-r-f n*-y7nm. Pyf-h-frtm pAT-f-Mnm. Pythium ariBtonpnmm. Pvthiwp *ph*nidermatvm * damping-off, * root rot, * young plant collar rot. Thie invention further relates to fungicidal compositions intended for protecting seeds, preferably of monocotyledon plants, against fungal diseases, characterised in that they contain: «-• • at least one active material chosen from the group consisting of phosphorous acid or its salts, * at least one inert vehicle which is acceptable in agriculture and, * optionally a surface-active agent which is acceptable in agriculture, * the various constituents of these compositions being other than the triazole 2-(4-chlorobenzylidene)-5,5-dimethyl-l-(lH-l,2,4-triazol-l-ylmethyl)-1-cyclopentanol. 260 826 The compositions used in the invention commonly contain between 0.5 and 95% (by weight) of active material of phosphorous type. Preferably, the amount of active material of phosphorous type in these treatment formulations is greater 5 than 5% (by weight). The present invention also relates to a process for protecting seeds, or other propagation material excluding seedlings or roots, preferably of monocotyledon plants, against a fungal disease, characterized in that an effective amount of 10 fungicidal active material and/or of fungicidal compositions as defined above is applied to the said seeds. According to this process of the invention, application of the fungicidal active material of phosphorous type is carried out using compositions comprising at least 5% of active material of phosphorous type, 15 preferably at least 10%. In the present account, the term "vehicle" denotes a natural or synthetic, organic or inorganic material with which the active material is combined to facilitate its application to the seed. This vehicle is thus generally inert and it must 20 be acceptable in agriculture, especially on the treated seed. The vehicle can be solid (clays, natural or synthetic silicates, silica, resins, waxes, solid fertilizers and the like) or, preferably, liquid (water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, 25 chlorinated hydrocarbons, and the like). As has been said above, liquid vehicles are preferred, 260826 in particular those in which the phosphorous active material is soluble, more especially water and aqueous solutions. The surface-active agent can be an 5 emulsifying, dispersing or wetting agent of ionic or nonionic type. There may be mentioned, for example, salts of polyacrylic acids, salts of lignosulphonic acids, salts of phenolsulphonic or naphthalenesulphonic acids, polycondensates of ethylene oxide with fatty 10 alcohols or with fatty acids or with fatty amines, substituted phenols (especially alkylphenols or arylphenols) , salts of esters of sulphosuccinic acids, taurine derivatives (especially alkyltaurates), or phosphoric esters of polyoxyethylenated phenols or 15 alcohols. The presence of at least one surface-active agent is often required. These compositions can also contain any kind of other ingredients such as, for example, protective colloids, adhesives, thickening agents, thixotropic 20 agents, penetrating agents, stabilizing agents, sequestering agents, pigments, dyes or polymers. More generally, the compositions . can be combined with all the solid or liquid additives corresponding to the conventional 25 formulating techniques for application of seed treatment in particular. While on this subject, it will be noted that. in the vocabulary of those skilled in the art, the^teria ° A>v\ ■' . ... 2608 seed treatment in fact mainly relates to the treatment of seed grains. The application techniques are well known to those skilled in the art and they can be used without 5 disadvantage in the context of the present invention. Mention may be made, for example, of film-coating or coating. Coating is preferred in the invention because of its simplicity; it is sufficient to stir or zoix the seed to be treated with the 10 fungicidal compositions* Among the compositions, solid or liquid compositions may generally be mentioned. There may be mentioned, as forms of liquid compositions or those intended to constitute liquid 15 compositions at the time of application, solutions> in particular water-soluble concentrates, emulsifiable concentrates, emulsions, suspension concentrates or wettable powders (or powder to be sprayed) . The emulsifiable or soluble concentrates most 20 often comprise 10 to 80% of active material while emulsions or solutions ready for application contain, for their part, 0.01 to 20% of active material. For example, in addition to the solvent, the emulsifiable concentrates can contain, when this is 25 necessary, 2 to 20% of suitable additives such as stabilizing agents, surface-active agents, penetrating agents, corrosion inhibitors, dyes or the abovementioned adhesives. \ 260826 8 From these concentrates, it is possible to obtain, by dilution with water, emulsions of any desired concentration, which are particularly suitable for application to seeds. The wettable powders (or powder to be sprayed) are generally prepared so that they contain 20 to 95% of active material, and they generally contain, in addition to the solid vehicle, from 0 to 5% of a wetting agent, from 3 to 10% of a dispersing agent and, when this is necessary, from 0 to 10% of one or more stabilizing agents and/or other additives, such as pigments, dyes, penetrating agents, adhesives, antidumping agents, and the like. As has already been said, aqueous dispersions and emulsions, for exasg>le the compositions obtained by diluting a wettable powder or an emulsifiable concentrate with water, may be used in the present invention. Emulsions can be of the water-in-oil or oil-in-water type and they can have a thick consistency, like that of a "mayonnaise". Among these compositions, a person skilled in the art will advantageously choose that or those which are suitable depending on the conditions of use. In the invention, the phosphorous derivative can be used alone or as a mixture, in particular with fungicides or insecticides, especially captan, thiram, aspirin or its salts and esters, salicylic acid or 9 26 0 8 2 6 salts and esters, guasatine, oxine-copper, tefluthrin, anthraquinone or metalaxyl, and insecticides such as imidacloprid, lindane and endosulfan, as veil as mixtures of these various products. 5 The following Examples illustrate the invention. Example 1 100 g of barley seed grains were treated with 1.5 ml of an aqueous phosphorous aoid or sodium 10 monophosphite (NaH2P03) solution. The concentration of the treatment solution was oaloulated so as to obtain, on the seed, the dosage (in g/q) of product shown in the Table below. For a dosage of 100 g/q, the concentration of phosphorous acid in the water was 15 75 g/1. The treatment was carried out by simple mixing/stirring, for 1 min, so as to obtain seeds comprising various concentrations of phosphorous acid as shown in the Table below. 20 These seed grains were deposited in pots containing a mixture of peat and pozzolana. one millilitre of Pythium mycelium ground preparation was inoculated into each pot by spraying the earth. There were approximately 20 seed grains per pot. 25 The seed grains germinated and, 15 days after sowing, the state of the plants was observed with V,'! C / respect to control seed grains not treated with h<5- phosphorous acid and with respect to control seed*^ ^ O, 10 260 82 6 grains not inoculated with Pvthium. All the plants which had survived had two leaves. Mo phytotoxicity was observed in any case. The results were the following! Fungicidal Dose in Efficiency expressed as agent g/q percentage * Pvthium Pvthium arrhenomanes mvriotvlum Phosphorous 50 60 40 acid 100 100 60 Sodium 100 75 20 monophosphite 200 100 70 400 100 100 800 100 100 Untreated 0 0 0 control inoculated with Pvthium •i.e. the number of surviving treated seedl ings expressed as a percentage of the number of surviving seedlings which had received neither the fungicidal agent nor the inoculation with Pvthium. Example 2 Barley seed grains were treated, as in Example 1, with aqueous dipotassium phosphite solutio' </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 26 0 82 6 To obtain a dosage of 240 g/q of product on the seeds, 100 g of seeds were treated with 1.5 ml of a solution containing 80 g/1 of x^HPOj. The seed grains thus treated were sown in an open field and the state of the crop was observed 72 days after sowing with respeot to an untreated control. Both crops were affected by fungal attacks of Pvthium arrhenomanes. As compared with the untreated plants, the plants treated according to the invention contained 2.8 times more roots and were greater in number by 24.3%. The weight of dry matter of the roots of the treated plants compared with the untreated plants was greater by 39%. 260826 12 WHAT WE CLAIM IS:

1. Plant seeds or other propagation material excluding seedlings or roots comprising, as a fungicide, phosphorous acid or a salt thereof. 1 5

2. Plaint seeds according to claim 1 which are monocotyledonous.

3. Seeds according to claim 2 which are cereal seeds.

4. Seeds according to claim 2 which are wheat, barley, rye, winter barley, oats, triticale, maize or rice seeds. 10

5. Seeds according to claim 1, 2, 3 or 4 which comprise phosphorous acid or an alkali metal or ammonium salt thereof.

6. Seeds according to claim 1, 2, 3 or 4 which comprise a phosphorous acid salt having a solubility in water at 20°C greater than 0.1 g/1. 15

7. Seeds according to claim 6 wherein the solubility is greater than 0.5 g/1.

8. Seeds according to any one of claims 1 to 7, which comprise from 1 g/quintal to 1 kg/quintal of the phosphorous acid or salt thereof. 26 Q B id 6 13

9. Seeds according to claim 8 which comprise from 5 to 500 g/quintal of the phosphorous acid or salt thereof.

10. Seeds according to any one of claims 1 to 9, which also 5 comprise a second active material chosen from captan, thiram, guazatine, oxine-copper, metalaxyl, imidacloprid, lindane and endosulfan.

11. Seeds according to any one of claims 1 to 9, which also 10 comprise a second active material chosen from aspirin, its salts and esters and salicylic acid and its salts and esters.

12. A method for protecting seeds or other propagation material excluding seedlings or roots against a fungal disease, 15 which comprises applying thereto an effective amount of phosphorous acid or a salt thereof.

13. A method according to claim 12 wherein the seeds or other propagation material are of monocotyledon plants. 20

14. A method according to claim 12 or 13 wherein the fungal disease is 25 * a disease caused by Pvthium arrhenomanes. Pvthium araminicola. Pvthium torulosum.;Pvthium vanterpoolii. Pvthium mvriotvlum. Pvthium periilum. Pvthium aristosporum. or Pvthium aphanidermatum.;260 826;5 15- Young plants, resulting from the germination of seed according to any one of claims 1 to 11 or treated by the method of claim 12, 13 or 14.;16. Plant seeds as claimed in claim 1 substantially as herein 10 described with reference to any example thereof.;17. A method for protecting seeds or other propagation material as claimed in claim 12 substantially as herein described with reference to any example thereof.;15;RHONE.-1*3. ilEMC- -Asperate- By the authorised agents A. J Rark & Son Per^e^_. damping-off, root rot, or young plant collar rot. </div>